It's already there.
840
840
27844 rounds to30 000 to the nearest ten thousand28 000 to the nearest thousand27 800 to the nearest hundred27 840 to the nearest ten
840
840
840
840
840
840
It is already rounded to the nearest ten as 840
850
840
145
840
It is: 850
840
27844 rounds to30 000 to the nearest ten thousand28 000 to the nearest thousand27 800 to the nearest hundred27 840 to the nearest ten